The overall objective of this proposal is to develop a novel implanted auditory assist device that will specifically address age related strial hearing loss. As people age, many experience a hearing loss, strial presbycusis, across all frequencies. The relationship between the rise in hearing thresholds and the corresponding reduction in the endocochlear potential is well documented. Recent research on animals demonstrates that increasing the endocochlear potential back to its normal value results in the decrease of hearing thresholds back towards their normal values. We propose to develop a hearing assist device based on this new research. The implanted device will maintain the endocochlear potential at near normal values in the ears of older people who suffer from strial hearing loss, thereby reversing their hearing impairment. In addition, there are early indications that this device will not only reverse hearing loss, but also serve as a therapy for strial presbycusis by preventing further deterioration of the scala media.